Kate Middleton dazzles in Alexander McQueen and Princess Diana's tiara for Trump state banquet

The royal family is pulling out all the stops for President Trump's three-day state visit to the UK this week. For the Windsors, that means a tour of Westminster Abbey, tea at Clarence House and, of course, the state banquet on Monday night. Dignitaries and royals gathered at Buckingham Palace to hear speeches from both President Trump and Her Majesty during the black-tie affair.

While the Duchess of Cambridge wasn't there to welcome the Trumps to Buckingham Palace or Westminster Abbey, the mum-of-three was spotted arriving at the affair alongside Prince William. The 37-year-old royal opted for a gorgeous all-white gown by her go-to designer Alexander McQueen, which she paired with Princess Diana's Lovers Knot tiara and the Queen Mother's sapphire and diamond earrings.

Kate also debuted her sash of the Royal Victorian Order for the first time, which she was honoured with by Queen Elizabeth last year for her work and dedication to the royal family.

The royal was paired with Secretary of the Treasury Steve Mnuchin for the banquet -- the two entered the hall side by side and were seated next to each other for the dinner.